Fluoranthene Biodegradation by Serratia sp. AC-11 Immobilized into Chitosan Beads

Abstract

The intensive production of polycyclic aromatic hydrocarbons by anthropogenic activities is a serious environmental problem. Therefore, new bioremediation methods are required to avoid widespread contamination. In this work, Serratia sp. AC-11 strain isolated from a tropical peat was selected for immobilization into chitosan beads, which were employed in the biodegradation of fluoranthene. The sizes of the produced beads were relatively uniform with an average diameter of 3 mm. The material was characterized by SEM and FT-IR, confirming the cells immobilization and the protective barrier formed by the chitosan surrounding the biomass. The immobilized bacteria were able to degrade 56% of fluoranthene (the initial concentration was 100 mg L −1) in just 1 day at twice the degradation rate achieved by freeliving cells. Furthermore, the immobilized bacteria showed excellent removal during five reuse cycles, from 76% to 59% of biodegradation. These results showed the potential of this approach for remediation of contaminated sites.

Chitin- and Chitosan-Based Derivatives in Plant Protection against Biotic and Abiotic Stresses and in Recovery of Contaminated Soil and Water

“…W4-01 strain immobilized in chitosan-activated carbon beads can remove diesel oil from contaminated water [56], while bacteria of Serratia sp. AC-11 strain immobilized in similar beads can degrade polycyclic aromatic hydrocarbons [57] more efficiently than the free-living cells. Interestingly, a novel amphiphilic nanocomposite material covered by chitosan can degrade trichloroethylene [58], suggesting a possible use of this approach for air decontamination, too, and addition of chitin-rich crustacean shells to soil can positively affect microbial and fungal communities, helping biodegradation of aromatic compounds [59].…”